Scientific Principles Mock 2 PDF

# SCIENTIFIC PRINCIPLES MOCK 2 ## Multiple Choice Questions 1. Water freezes at - a) 0°C - b) 16°C - c) 25°C - d) 32°C. 2. Water reaches its maximum density at - a) 0°C - b) 2°C - c) 4°C - d) 8°C. 3. A tap fitted to a bath mixer has a head of water 3.0 metres abo...

# SCIENTIFIC PRINCIPLES MOCK 2 ## Multiple Choice Questions 1. Water freezes at - a) 0°C - b) 16°C - c) 25°C - d) 32°C. 2. Water reaches its maximum density at - a) 0°C - b) 2°C - c) 4°C - d) 8°C. 3. A tap fitted to a bath mixer has a head of water 3.0 metres above it. What is the approximate pressure at the tap? - a) 0.1 Bar. - b) 0.3 Bar. - c) 1.0 Bar. - d) 3.0 Bar. **Figure 1** shows a vertical pipe with 4 holes at different elevations. 4. Refer to Figure 1. Given that all holes have the same diameter, the water pressure is greatest at hole - a) A - b) B - c) C - d) D. 5. The pipe material that offers the greatest resistance to water flow is - a) grade X copper - b) grade Z copper - c) PVC-U - d) galvanised LCS. 6. The process of siphonage utilises - a) atmospheric pressure - b) specific gravity - c) capillary action - d) vacuum pumps. 7. Which one of the following should be used to measure the temperature of flow and return pipework in a heating system? - a) Clip on thermometer. - b) Mercury wall thermometer. - c) Bimetallic strip. - d) Phial of heat sensitive gas. 8. Copper has a specific heat capacity of 0.385 kJ/kg °C. The amount of heat energy needed to heat 1 kg of copper by 2°C is - a) 0.385 kJ - b) 0.77 kJ - c) 3.85 kJ - d) 7.7 kJ. **Q = m.C.ΔT = 1.0385.2 = 0.77kJ** 9. Which of the following most accurately describes the way in which heat is transferred by radiation? - a) Heat transfer to a body in straight lines. - b) Transfer of heat energy through solids. - c) Transfer of heat through a fluid substance. - d) Heat transfer through chemical reaction. 10. Permanent hardness in water is caused by the - a) permeation of rainwater through peat - b) solvent ability of water to dissolve minerals from sandstone - c) solvent ability of water to dissolve calcium sulphate - d) solvent ability of water to dissolve calcium carbonate. 11. The direct result of hard water in domestic properties is most likely to be - a) reduced system efficiency - b) water hammer - c) persistent running overflow - d) water that will produce a lather. 12. The effect of electrolytic action upon a type of metal is dependent upon the - a) specific gravity of the metal - b) number of electrons present in one atom of the metal - c) position of the metal in the electromotive series - d) melting point of the metal. **Figure 2** shows four tubes labelled A, B, C and D. 13. Refer to Figure 2. Capillary attraction would be greatest in tube - a) A - b) B - c) C - d) D. 14. Relative density is the - a) force exerted by the density of a substance - b) density of a substance in comparison to the density of water - c) density of water displaced when a substance is placed in water - d) density of a substance divided by its volume. 15. Which one of the following metals has the highest rate of heat conductivity? - a) Steel. - b) Copper. - c) Lead. - d) Iron. 16. Which one of the following metals needs to be treated if it is exposed to the effects of atmospheric corrosion? - a) Iron. - b) Lead. - c) Galvanised steel. - d) Zinc. 17. During electrolytic action the - a) anode will gradually destroy the cathode - b) electrolyte will destroy the cathode - c) electrolyte will be used up and disappear - d) cathode will gradually destroy the anode. 18. What is the fuse rating for a 600 watt appliance on a 220 volt supply? - a) 1 amp. - b) 3 amp. - c) 6 amp. - d) 13 amp. **I = P/V = 600/220 ≈ 2.73 amps** 19. Socket outlets in a domestic property usually have a maximum amp rating of - a) 6 amps - b) 9 amps - c) 13 amps - d) 15 amps. 20. It would be most appropriate for a plumber to use temporary earth continuity bonds when - a) flushing a domestic hot water system - b) working on a central heating control panel - c) changing a cold water tap washer - d) removing a section of system pipework.